无废话WPF系列10: Binding对数据的检验

设置Binding的ValidationRules属性对Binding进行检验

 <StackPanel>

        <TextBox x:Name="txtAge" FontSize="30" Foreground="Red"></TextBox>

        <TextBlock x:Name="errorSummary" FontSize="30" Foreground="Red"></TextBlock>

</StackPanel>

 

后台代码

public partial class MainWindow : Window

    {

        

        public MainWindow()

        {

            InitializeComponent();

            Person p = new Person { Age = 20, Name = "Tom" };

            Binding binding = new Binding("Age") { Source = p };



            binding.NotifyOnValidationError = true;



            binding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;

            RangeValidationRule rv = new RangeValidationRule();

            binding.ValidationRules.Add(rv);

            this.txtAge.SetBinding(TextBox.TextProperty, binding);



            this.txtAge.AddHandler(Validation.ErrorEvent, new RoutedEventHandler(this.ValidationError));

        }



        void ValidationError(object sender, RoutedEventArgs e)

        {

            if (Validation.GetErrors(this.txtAge).Count > 0)

            {

                this.txtAge.ToolTip = Validation.GetErrors(this.txtAge)[0].ErrorContent.ToString();

                this.errorSummary.Text = Validation.GetErrors(this.txtAge)[0].ErrorContent.ToString();

                // You can do everything here when validation error occurs

            }

        }

        

    }

}

 

 

同样，我们在XAML里也可以设置验证

<StackPanel>

        <TextBox x:Name="txtAge" FontSize="30" Foreground="Red"   Validation.Error="txtAge_Error">

            <Binding NotifyOnValidationError="True" Path="Age" UpdateSourceTrigger="PropertyChanged">

                <Binding.ValidationRules>

                    <local:RangeValidationRule></local:RangeValidationRule>

                </Binding.ValidationRules>

            </Binding>

        </TextBox>

        <TextBlock x:Name="errorSummary" FontSize="30" Foreground="Red"></TextBlock>

</StackPanel>

 

后台代码：

public partial class MainWindow : Window

    {        

        public MainWindow()

        {

            InitializeComponent();

            Person p = new Person { Age = 20, Name = "Tom" };

            this.DataContext = p;           

        }        

        private void txtAge_Error(object sender, ValidationErrorEventArgs e)

        {

            if (Validation.GetErrors(this.txtAge).Count > 0)

            {

                this.txtAge.ToolTip = Validation.GetErrors(this.txtAge)[0].ErrorContent.ToString();



                this.errorSummary.Text = Validation.GetErrors(this.txtAge)[0].ErrorContent.ToString();

                // You can do everything here when validation error occurs

            }

        }        

}